ae_addMarkers

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is carried by structured data. The description adds nothing beyond that: it doesn't say whether existing markers at the same time are overwritten, whether time is seconds or frames, or how markers are ordered — all real behavioral questions for a mutation on a timeline.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with the app, verb and resource first, then the payload shape, then an example. Nothing is padded, though the inline bracket notation adds visual noise without conveying much the schema doesn't already say.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a mutating tool with no output schema, and the description doesn't say what comes back (created marker count? updated marker list?) or whether the call is idempotent when markers collide. For a marker-creation call where unit interpretation determines correctness, the definition leaves too much for the agent to guess.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 67%, so the schema documents 'layer' and 'compositionName'; the description instead re-lists the marker object fields already present in the nested schema and omits the two documented params entirely. The most important ambiguity — units and basis for 'time' (seconds vs frames, relative to comp start) — is left unresolved in both schema and description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('add comp or layer markers') and the 'After Effects:' prefix separates it from the Premiere sibling pr_addMarkers. The bracket-list of marker fields is a bit cryptic but the core action is unmistakable and distinguishable from ae_getMarkers/ae_deleteMarkers.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'e.g. VO word/sync markers' implies a usage context, so an agent can infer this is for annotating timing sync points. However there is no explicit when-to-use vs. when-not guidance, no mention of the ae_getMarkers/ae_deleteMarkers siblings, and no prerequisites (e.g. must a comp be open?).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.